I havent read the manga yet Im trying to stay away for it since I like not knowing whats gonna happen, same with Nabari. 47 chaps in 3 days is pretty good. Sounds like when I read vols 9-16 of KHR is about 4 days
I spoke with the translator of the Missing novel series. He said that the first few volumes of the Japanese novel series were written as standalones because they didn't know for sure that the series would be continued. So Missing novel 1 is the complete version of the manga 3 volumes. He also told me that novel 2 is a complete story as well. If English version novel 3 ever comes out, it will be a combined version of Japanese novels 3 and 4 making for a complete story. (Think of the last two GH novels combined into one book.) Missing novel 2 will be a new story altogether featuring the same characters (the literary club). Whether Missing novel 1's ending is any less rushed than the manga version's ending, I can't say because I haven't read it yet.
I did like His Majesty and the other guys flashback scene but for me the ending was too...blah. I dunno, it felt rushed and left too much open. I get that it only covers a bit of the novels and the novels go into further detail but I dunno, I wasnt too happy with the ending. I debated getting the novel series since I normally dont buy anime novels but seeing that it got cancelled, I think Ill stay back from it.